The Use of Electromagnetic Induction Proximal Soil Sensing to Gain Insights into Spatial Variability in Vineyard Fertility and Productivity

Abstract:

Knowledge of spatial variability in vine productivity such as vine vigor, yield, and mortality is crucial for efficient management of vineyards to reduce production costs as well as environmental impact. Soil cation exchange capacity (CEC) is a measure of the ability of soils to hold cations that relate to soil fertility, such as nutrient availability, pH, structure stability, and how the soil will respond to different ameliorants such as lime, gypsum, and fertilizer applications. The conventional approach to estimating CEC is, however, time-consuming, expensive, and limited in spatial resolution. Electromagnetic induction (EMI) measurement of soil electrical conductivity (EC) and magnetic susceptibility (MS) provide an alternative approach to inexpensively obtain spatially continuous profiles of the underlying soil properties within a vineyard in a rapid and non-invasive fashion. To understand spatial variability in soil fertility, we perform cluster analysis of sparse measurement of soil CEC in the 2D space of EC and MS, and subsequently creates vineyard management zones from the high resolution EC and MS maps. We apply normalized difference vegetation index (NDVI) as a proxy to assess vine productivity to relate to the management zones.

In this study, we performed EMI surveys of four commercial vineyards in the Finger Lakes region of New York. We collected a total of 85 soil samples for laboratory analysis of CEC, soil organic matter, and pH. We calculated NDVI for the fields from 10 m spatial resolution of Sentinel-2 imagery to demonstrate that EMI proximal soil sensing can unravel spatially continuous variability in vineyard fertility and productivity to guide the creation of management zones to support decision making in vineyard management practices.